Microsoft has historically had a reputation as being a tough place to work, due to infighting, staff fragmentation and cutthroat office politics. Steve Ballmer, Nadella's predecessor, set in motion his own culture-changing effort, called One Microsoft, shortly before announcing his retirement.

It's not clear from Nadella's letter whether his plan builds on One Microsoft or sets it aside. Whatever the case, Nadella uses strong language to convey the need for the company to function in a more effective way.

He wants to make Microsoft a company where "smart, curious, ambitious people" can do "their best work."

This change in business culture is necessary for Microsoft to accomplish its goal to be the premier "productivity and platform company for the mobile first and cloud first world," serving people in their personal and work lives, he wrote.

While he went over many of the technology concepts he has been outlining since taking over as CEO in February, such as the emphasis on cloud and mobile computing, Nadella also explained for the first time that the vision of Microsoft as a "productivity and platform company" replaces its current description as a "devices and services" company. Microsoft will "reinvent productivity" for individuals and businesses worldwide, he wrote.

"Productivity for us goes well beyond documents, spreadsheets and slides. We will reinvent productivity for people who are swimming in a growing sea of devices, apps, data and social networks," he wrote.

Thus, Microsoft products will be tuned to the context in which customers work, so that they can be more predictive and helpful. "Every experience Microsoft builds will understand the rich context of an individual at work and in life," he wrote.

However, to accomplish these technology and product goals, Microsoft's culture needs a makeover.

"Nothing is off the table in how we think about shifting our culture to deliver on this core strategy. Organizations will change. Mergers and acquisitions will occur. Job responsibilities will evolve. New partnerships will be formed. Tired traditions will be questioned. Our priorities will be adjusted. New skills will be built. New ideas will be heard. New hires will be made. Processes will be simplified," he wrote. "And if you want to thrive at Microsoft and make a world impact, you and your team must add numerous more changes to this list that you will be enthusiastic about driving."

Specifically, Microsoft will "modernize" its engineering processes, so that they're more in tune with customer needs, and are more data driven, faster and more focused on quality, according to Nadella.

The goal is to "reduce the amount of time and energy it takes to get things done" in the engineering team by having fewer people involved in making decisions, and more accountability.

In addition, every engineering group will have "data and applied sciences" resources focused on measuring outcomes for products and predicting future trends, leading, according to Nadella, to better innovation.

Meanwhile, software engineering will evolve to let information travel faster "with fewer breaking points" between envisioning a product or service and delivering it to customers.

Microsoft will increase investments for employee training and development, and will encourage the testing of new ideas and incubation of new projects. It will become easier for employees to change roles within the company.

And Nadella is calling on every team at Microsoft to find ways to simplify the way they function and be faster and more efficient.

"We will increase the fluidity of information and ideas by taking actions to flatten the organization and develop leaner business processes," he wrote.

That goes for everyone in the company starting with him and his senior leadership team, Nadella wrote.

"Culture change means we will do things differently. Often people think that means everyone other than them. In reality, it means all of us taking a new approach and working together to make Microsoft better," he wrote.

After quoting a verse from poet Rainer Maria Rilke -- "The future enters into us, in order to transform itself in us, long before it happens" -- Nadella closed by calling on all employees to have courage to change.

"With the courage to transform individually, we will collectively transform this company and seize the great opportunity ahead," he wrote.

While Nadella laid out his vision for transforming Microsoft's culture with passion and eloquence, in reality most attempts at changing corporate cultures fall short or fail altogether, because the challenge is in making the concepts a reality.

So it will be interesting to see whether Nadella is able to accomplish this goal, or whether the ingrained Microsoft corporate culture is too difficult to transform at this point.